Knife for Circular Surgical Stapler

An apparatus includes a body, a shaft, and a stapling head assembly. The shaft extends distally from the body. The stapling head assembly is positioned at a distal end of the shaft. The stapling head assembly includes a staple driver member and a knife member. The staple driver member is configured to drive a plurality of staples into tissue. The knife member is configured to cut through the tissue. The knife member includes a proximal end, a distal end, and a cylindrical body extending between the proximal and distal ends. The cylindrical body includes at least one coupling feature that operatively couples the knife member with the staple driver member.